Frankfurt 2006 – wissenschaftliches Programm

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MO: Molekülphysik

MO 27: Poster: Femtosecond Spectroscopy

MO 27.11: Poster

Dienstag, 14. März 2006, 16:30–18:30, Labsaal

Dynamics of electron transfer through a chromophore/ semiconductor interface — •Liana Socaciu-Siebert, Antje Neubauer, Lars Gundlach, Jodi Szarko, Ralph Ernstorfer, Charaf Cherkouk, Guido Morbach, Rainer Eichberger, and Frank Willig — Hahn-Meitner Institut, Abteilung Dynamik von Grenzflächenreaktionen SE4, Glienicker Str. 100, 14109 Berlin, Germany

The ultrafast heterogeneous electron transfer through a chromophore/semiconductor interface was investigated by means of time-resolved two-photon photoemission spectroscopy (TR-2PPE). This pump-probe technique allowed for monitoring simultaneously the time evolution as well as the energy distribution of the injected electrons. The chromophore/semiconductor systems were chosen so that the first excited state of the molecule (donor state) was energetically positioned above the conduction band minimum of the semiconductor. The organic choromophores (perylene derivatives) were chemically anchored on the rutile TiO₂(110) surface. Different molecular groups, which acts as a bridge, were also inserted between the chromophore and the anchor. The electron transfer rate is strongly influenced by the length and structure of the molecular bridge and, subsequently, the injection times vary over a few orders of magnitude. A systematic study of the dynamics of electron transfer for chromophores with different molecular bridges is presented in this contribution.